Re: SDNV-new (was: Re: [dtn-security] 00 version of the Bundle Security Protocol Spec.)
Michael Demmer <demmer@cs.berkeley.edu> Wed, 25 May 2005 16:37 UTC
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Date: Wed, 25 May 2005 09:37:07 -0700
From: Michael Demmer <demmer@cs.berkeley.edu>
To: dtn-security@mailman.dtnrg.org
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Subject: Re: SDNV-new (was: Re: [dtn-security] 00 version of the Bundle Security Protocol Spec.)
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> I guess this could work ok. Whether its better or worse > than sdnv-8/sdnv-16 depends on the frequency with which > we're encoding values in the range 4096-65535, Actually, not quite. See below... > and of course, my code currently does the -8/-16 thing, so if > we're making this change, we'll want to do it in LTP > at the same time. That'd be fine with me of course. > Also - can you give some more examples of values > and how they're encoded - the description is a bit > opaque. Ok, here's some arbitrary examples that express some of the various cases. Note that for the discriminator byte of the SDNV binary, I put in a . character to separate the relevant pieces. value hex SDNV hex SDNV binary 10 0a 0a 0.000.1010 90 5a 5a 0.101.1010 197 c5 80 c5 1.000.0000 11000101 2099 833 88 33 1.000.1000 00110011 12345 3039 90 30 39 1.001.0000 00110000 00111001 456789 6f855 96 f8 55 1.001.0110 11111000 01010101 123456789 75bcd15 a7 5b cd 15 1.010.0111 01011011 11001101 00010101 So, as I see it, the relevant range is for the values like 2099, 456789, etc in which we encode the high-order nibble in the discriminator byte itself. With SDNV-8, the value 2099 requires three bytes, whereas with this scheme it requires only two. Similarly, 456789 would require four bytes with SDNV-8, but only three with this scheme, etc. > I don't think its really harder to code up use of > sdnv-8 or -16 though, nor are coders likely IMO to > get confused between these as long as we don't > oscillate between 'em at specification time. Agreed -- I don't think any one of these schemes is easier and/or harder to implement. My argument would be to settle on any one, but as long as we're consistent, I don't really care. It does, however, bring a naming question as to what to call this scheme... I don't think SDNV-new is all that appealing in the long run. -m
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Scott Burleigh
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Michael Demmer
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Rajesh Krishnan
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Scott Burleigh
- Re: [dtn-security] 00 version of the Bundle Secur… Scott Burleigh
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Michael Demmer
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Howard Weiss
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Rajesh Krishnan
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Scott Burleigh
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Michael Demmer
- Re: are offsets enough? --was: (dictionary or not… Michael Demmer
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Michael Demmer
- [dtn-security] Re: [dtn-dev] Re: SDNV-new Scott Burleigh
- I18N (was: Re: (dictionary or not) Re: [dtn-secur… Stephen Farrell
- [dtn-security] Re: are offsets enough? --was: (di… Stephen Farrell
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Stephen Farrell
- [dtn-security] Re: [dtn-dev] Re: SDNV-new Michael Demmer
- RE:are offsets enough? --was: (dictionary or not)… Susan F. Symington
- Re: [dtn-dev] Re: [dtn-security] 00 version of th… Michael Demmer
- [dtn-security] Re: [dtn-dev] Re: SDNV-new Michael Demmer
- Re: (dictionary or not) Re: [dtn-security] 00 ver… Scott Burleigh
- [dtn-security] Re: [dtn-dev] Re: SDNV-new Scott Burleigh
- Re: [dtn-dev] Re: [dtn-security] 00 version of th… Scott Burleigh
- Re: (dictionary or not) Re: [dtn-security] 00 ver… Michael Demmer
- Re: SDNV-new (was: Re: [dtn-security] 00 version … Michael Demmer
- Re: [dtn-security] 00 version of the Bundle Secur… Wesley Eddy
- SDNV-new (was: Re: [dtn-security] 00 version of t… Stephen Farrell
- Re: (dictionary or not) Re: [dtn-security] 00 ver… Stephen Farrell
- Re: (dictionary or not) Re: [dtn-security] 00 ver… Michael Demmer
- RE: [dtn-security] 00 version of the Bundle Secur… Susan F. Symington
- (dictionary or not) Re: [dtn-security] 00 version… Stephen Farrell
- Re: [dtn-security] 00 version of the Bundle Secur… Michael Demmer
- Re: [dtn-security] 00 version of the Bundle Secur… Michael Demmer
- Re: [dtn-security] 00 version of the Bundle Secur… Stephen Farrell
- [dtn-security] 00 version of the Bundle Security … Susan F. Symington
- Re: [dtn-security] Re: SDNV-new : OK Stephen Farrell
- Re: [dtn-security] 00 version of the Bundle Secur… Stephen Farrell
- [dtn-security] Re: SDNV-new : OK Manikantan Ramadas
- Re: [dtn-security] 00 version of the Bundle Secur… Howard Weiss
- Re: [dtn-security] 00 version of the Bundle Secur… Scott Burleigh
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new Manikantan Ramadas
- RE: [dtn-security] 00 version of the Bundle Secur… Susan F. Symington
- Re: [dtn-security] Re: [dtn-dev] Re: SDNV-new stephen.farrell
- Re: [dtn-security] meeting at IETF? Kevin Fall
- [dtn-security] meeting at IETF? Sandra Murphy